1. Field of the Invention
This invention relates to a method and an apparatus for automatic bacteriological cleaning and disinfection of objects.
More particularly the invention relates to a method of this type comprising sequential treating of the objects in compartments arranged one after the other for performing (during a cycle of operations) a sequential series of treatment operations, such as pre-flushing, washing, rinsing and drying. The objects are fed successively to the different compartments and are received by each compartment to be subjected to one of said operations therein, said operations of a cycle being performed simultaneously one in each compartment.
The invention also relates to an apparatus comprising a series of compartments, conveying means for feeding the objects sequentially to each of said compartments, and means for supplying treating medium to the objects when received by the different compartments.
2. Description of the Prior Art
Recently it has been found that the carriages used in hospitals or the like for transporting food from a central kitchen to patients in different hospital sections form a source for spreading bacteria and may be the cause of nosocomical infection. The same problem exists regarding the carriages used for transporting wash which may be seriously contaminated with bacteria from hospitals to central laundries.
So far the carriages used for the above purpose have been cleaned by methods which in no way meet the requirements of bacteriological cleaning set up for hospitals, and often the carriages have only been flushed manually with water. Since the carriages used for transporting food may reciprocate four times a day between the kitchen and the different hospital sections, it will be understod that bacteria collected on the carriages can be spread rapidly over a hospital in its entirety.
A prior-art apparatus for such cleaning and disinfection comprises a compartment in which the carriages are subjected to different treatment operations sequentially. First, the carriage is flushed and then it is sprayed by water containing a cleaner, possibly in combination with a physical treatment. When cleaner adhering to the carriage has been rinsed off, the carriage is dried. This type of apparatus is available both with open systems, i.e. liquid sprayed over the carriage is allowed to run off to a drainage, and closed systems, i.e. liquid sprayed over the carriage is collected to be used later.
The utilization of open systems has been preferred because bacteria, if any, which have collected in the water used in the different treatment steps follow the water entrained therein to the drainage. However, such systems are highly water and energy consuming because heated water is used in several treatment steps and is allowed to escape to the drainage. On the contrary, when closed systems are used considerably less water and energy is consumed but a great drawback is that bacteria washed off the carriage will collect in the water used at the different treatment steps whereby the cleaning effect deteriorates as the apparatus continues in operation. This prior art apparatus also has the drawback that only one carriage at a time can be cleaned and, therefore, the cleaning is time consuming.
Another prior art apparatus which has a larger capacity than that described above comprises a passage in which the carriages to be cleaned are fed continuously and, during such movement, are subjected to the different cleaning operations: pre-flushing, spraying with water containing a cleaner, rinsing and drying. This apparatus, too, is available with either closed or open systems, and, therefore, has the same drawbacks associated therewith as the apparatus described above. Moreover, in an apparatus of this type the use of open systems is not fully reliable from a bacteriological point of view because the carriage is moving during the different treatment operations whereby bacteria can be thrown or may flow together with the liquid used at the treatment from one end of the carriage to another in the feed direction of the carriage and thus can escape the cleaning action.